While its consequences are a major health problem, no treatment has proven consistently effective in eliminating smoking behavior. Evidence suggests this failure may be related in part to topographical factors in smoking, since certain types of smokers respond better to treatment than others. The proposed research will establish the reliability and validity of a new device for studying smoking topography. The device employs microcircuit technology to measure cigarettes/day and puffs/cigarette, as well as individual puff intervals, cigarette intervals, inter-puff intervals, and inter-cigarette intervals in subjects during their normal daily lives. Initial studies will be conducted under controlled hospital conditions using research cigarettes with known nicotine and other chemical composition to establish the reliability and validity of the portable recording device. Smoking topography will be determined for the same subjects under controlled hospital conditions and after hospital discharge, and will be used along with other measures to assess compliance in use of the smoking recorder. As part of the initial validation studies, the relation between the above topographical measures and total smoke exposure (volume of lung exposure) also will be ascertained. After completion of the initial studies, the smoking recorder will be used with subjects in their normal environment to determine treatment effects on smoking topography, in assessing the overall effectiveness of a common smoking treatment strategy. The research findings should improve our understanding of factors related to smoking treatment success, and have direct application to the development and evaluation of more effective treatment programs for the elimination of smoking behavior.